Dress appropriately for the industry; err on the side of being conservative to show you take the interview seriously. Your personal grooming and cleanliness should be impeccable.
Know the exact time and location of your interview; know how long it takes to get there, park, find a rest room to freshen up, etc.
Arrive early; 10 minutes prior to the interview start time.
Treat other people you encounter with courtesy and respect. Their opinions of you might be solicited during hiring decisions.
Offer a firm handshake, make eye contact, and have a friendly expression when you are greeted by your interviewer.
Listen to be sure you understand your interviewer's name and the correct pronunciation.
Even when your interviewer gives you a first and last name, address your interviewer by title (Ms., Mr., Dr.) and last name, until invited to do otherwise.
Maintain good eye contact during the interview.
Sit still in your seat; avoid fidgeting and slouching.
Respond to questions and back up your statements about yourself with specific examples whenever possible.
Ask for clarification if you don't understand a question.
Be thorough in your responses, while being concise in your wording.
Be honest and be yourself — your best professional self. Dishonesty gets discovered and is grounds for withdrawing job offers and for firing. You want a good match between yourself and your employer. If you get hired by acting like someone other than yourself, you and your employer will both be unhappy.
Treat the interview seriously and as though you are truly interested in the employer and the opportunity presented.
Exhibit a positive attitude. The interviewer is evaluating you as a potential co-worker. Behave like someone you would want to work with.
Have intelligent questions prepared to ask the interviewer. Having done your research about the employer in advance, ask questions which...